The present invention relates to a vehicular air conditioning apparatus having an air conditioning case into which air flows substantially parallel to a core surface of a heat exchanger.
In a vehicular air conditioning apparatus disclosed in JP-A-9-309320, air flows into an air conditioning case from an air intake port substantially parallel to an evaporator core surface housed in the air conditioning case.
In this kind of air conditioning case, a vertical dimension of the air intake port is smaller than a vertical dimension of the core surface. Thus, air expands largely in the vertical direction in the air conditioning case right after passing through the air intake port. The air flows toward and passes through the core surface. However, if distribution of air flow speed passing through the core surface is unbalanced over the core surface, it is likely to be difficult to control temperature of air blown into a passenger compartment.
It is an object of the present invention to provide a vehicular air conditioning apparatus having an air conditioning case into which air flows substantially parallel to a core surface of a heat exchanger for cooling and in which the air is equally distributed over the core surface to pass through the core surface, without increasing air blowing noise.
According to an air conditioning apparatus for a vehicle, an air conditioning case includes an upstream portion defining an air intake space upstream in an air passage. A heat exchanger is provided in the air passage downstream from the upstream portion. The heat exchanger has a core surface through which air flows. The core surface has a dimension H2 in a predetermined direction. The upstream portion defines an air intake port having a dimension H1 in a direction substantially parallel to the predetermined direction. The dimension H1 is smaller than the dimension H2 of the core surface. The air intake space includes a first space that corresponds to the air intake port in the predetermined direction and a second space other than the first space. Also, the upstream portion has an air flow direction changing portion protruding within the second space at a position opposing the core surface with a predetermined clearance.
In the upstream portion, air passed through the air intake port partially flows into the second space and further the air partially turns in a direction substantially parallel to the core surface. The turned air strikes the air flow direction changing portion, thereby changing its flow direction toward the core surface.
Since the upstream portion has the air flow direction changing portion, air flow speed passing through the core surface does not decrease at a downstream side of the turned air flow. Therefore, equalization of distribution of the air flow speed passing through the core surface improves. Further, since the dimension H1 of the air intake port is smaller than the dimension H2 of the core surface, the equalization of the air flow speed distribution improves without increasing air blowing noise.